Alloy structure



RMOll sensor 1912-1.

f mm STATES PATENT orrics.

new! 1:. wmmns m .anrnnn n nenennom), 03* micron: onro, sssrsnons roennnnar. norons nnsnancn conronnrron, or mar-res, 03m, A conscnarron Q1DELAWARE.

' ALLOY SEEM The present invention relate; to porous alloy structuresand relntesparficularly to hearing materials composed entirely orlargely of such porous alloys.

Among the objects of the present irwen lien is to increase the strengthof such alloys over that of similar materials heretofore produced whilemaintaining an equal or even greater porosity. V

Another object of the invention is to reu der the process of producingthe materials more economical and cii'icientand at the same time toproduce a better material.

with these and other objects, which will apprnr hereinafter, theinvention consists broadly in mixing :1 mos of fine metal particles witha smaller proportion of material that decomposes when heated, liberatinga non-corrosive gas and leaving as a residue a refractory material inrr:to the metallic particles end incapable of cohering to them. molding themas under pressure to a desired form and then heating the molded formsufiicicntly to cause the metallic particles to unite one to another andthe other material to decompose; thereby producing a strong body ofporous metal the pores or interstices of which contain particles ofinertrefractory filling material.

In applications, Serial Nos. 582.550 and 613380 filed in the names ofHarry M. Williams and Alfred L. BOQfIBlIOlfl. proc esses of producingporous alloy articles have been described and claimed.

The present recess is analogous to those processes elren 3 described butdiil'ers in that somewhat rlifierent materials are used and somewhatdifi'erent, processes The analogy lies in the fact that powered metalsand snpporting filler are compressed together and the compressed articleheated to en alloying temperature.

In the present process as in the former ones, a mint-um is made offinely divided metals, preferably copper and tin, in the proportions of90 parts by weight of copper to 10 parts by weight of tin, and finelypowdered non-alloying material. The so Application one s in .8, 2923.56m 30. saemz.

prepared mixture is wmpreswd into form in suitable dies under s prexrreof around 25300 to 80,669 pounds per square inch. After the compressi nstep, the compressed article is packed in carbonaceous material andheated to a temperature ofahont 1350 F. f r a period of about fivehours. -Attcr the artile has become cool enough to bandlc. it. ismuorcrl frnmtho carbonaceous packing and. if a bustling. is sized, forexample. by forcing through a. die n a mandreL This latter operationsimu taneonsly sizes the hashing, boil: inside and outsulc. I

In the prcmni process, instead f the nonallnying materials mentioned inthese former applications, namely, graphite. mica, snap stone, talc,etc, a material is nscrl which, under the conditions of the process, isdecomposed with liberation of a ron-corrosive -vol:itile substanceleaving as a residue r. ma-

terial inert to the other constituents present and capable of acting asa supporting filler for the hearing material. For this purpose,

a number of cla ses of materials may he used and among these chsses arethe carbonates (including the hicarkuates and basic carbonates).hydrates or hydroxides e. g., calcinm hydroxide), nitrates (e. g, coppernitrate), etc. of the All materials of these classes which fulfill theconditions just mentioned. upon decomposing, leave tehind metal oxidesto act as the supporting filler. However. the material preferred to beused is magnsinm carbonate. This material in the heating step becomesdecomposed giving off carbon dioxide leaving magnesium oxide behind.

The magnesium oxide acts as an excellent supporting material for thebearing and the carbon dioxide being liberated in the intersticesbetween the metal particles tends to increase the porosity of thefinished article and also apparently assists in the alloying, probablybecause of the non-oxidizing charactor of the gas under thoseconditions.

A specific example of the roportions used in making t pref r ec rorm ofbearing coming the present is the "following:

' $1? Copper powder W. 90 Tin powder 10 Magnesium carbonate... 4

a, for example, bung pable of absorbing n over one percent byweight ofoil and one which is quitchigh in strength and has a varying life evenunder quite trying conditions I Another example, one in which the poresity is. increased by mulling use of a proces of one of the priorapplications, is as follows:

Copper powder 90 In this latter example, the salicylic acid volatilizesin the heating step and this, in addition t: the d de. M nation 0 our nioxi very 4 increases the porosity of the final product.

The bearings having these roportions of constituents are capable of arbing close to five percent by weight of oil.

Magnesium carbonate has been mentioned as the preferred non-alloyingmaterial for use in carrying out the prsent invention, and thedescription confined largely to this substance, but it should beunderstood that the invention is not limited to it, as many othersubstances, as indicated above, have been used to make satisfactorybearing materials Magnesium carbonate has been chosen as the mostpreferable one because of the fact that it liberates gaseous carbondioxide upon being heated leaving a residue which serves as an excellentsupporting filler. Another advantage in the use of magnesium carbonateis that it works well in the compressnre dies.

Further, while the de cription has been confined chiefly to thepreferred processes and compositions it should be understood that; otherprocesses and compositions might be adopted all of which come within thescope of the claims which follow.

What we claim is as follows:

1. The process of producing bearing materials which comprises intimatelyfinely divided alloyable metals and a finely divided non-alloyingmaterial of itself rosity caused by the 611ml 1 give off a.non-corrosive volatile substance tion, a residue capable of acting as asupporting filler for the bearing material; compressing the mixture; andbeatin. under nonoxidizing conditions to cause]; e said decompositionand also alloying of the metals.

3. The procem of producing bearing materials which comprlsm iutimateling-finely divided alloyeble motels and divided magnesium carbonatecompressing the mixture;

carbonate and also alloying of the metals. 4. The process of producingbearing materials which comprises intimately mixing finely dividedcopper and tin and a finely divided magnesium carbonate; compressing themixture; and beefing under non-oxidizing'conditions to causedecomposition of the carbonate and also alloying of the metals.

e 5. The process of producing porous metallic structures capable ofreteming liquid in the pores, which consifi or intimately mi..- ing fineparticles of metal capable of uniting when subjected to relatively hightemperaturcs. with a final divided material incapable of cohering tosaid particles of metal, but capable oi deCOILDtElIIg at said relativelyhigh temperatures to site all a non-corrosive volatile substance andleaving a. residue which functions as a supporting filler for themetallic mass whenunion of the particles has been effected; compressingsaid mixture into a mass of the desired form and heating the form"sufiiciently to effect union of the metallic particles anddecomposition of the material mixed with them.

6. The process of producing porous metal structures capable of retainingliquid in the pores, which consists of intimately mixing fine particlesof metal capable of uniting when subjected to relatively high tempera.-fures, with finely divided magnesium carbonate. compressing said mixtureinto a mass of the desired form and heating the form sufiiciently toeffect union of the metallic and heating under non-oxidiu mg condltionsto cause decomposrtxon of the and to leave, as the result of itsdislntegreparticles and decompotion of the magnea metal oxide and havinga. capacity for sharia-p601: of oil in'amozmts exceeding one percent ofits weight. L .e

8. A hearing matenal comprising an 11110 I having naiformly distributedtherethrou mgnesium oxideand having a capacity or absorption of oilamounts ex one peanut of its weight.

9. A bearing material comprising a bronze having ufiformly dhiributedtherethmugh 10 magnesium oxide and having a mpacity for absorption ofoil in amounts exceeding one percent of its weight. In testimony whereofwe herein afiix our signatures.

' -HARRY M.

ALFRED L. BOEGEHOLD.

